枯草芽孢杆菌ON-6菌株抑制荔枝炭疽菌活性物质的初步研究

Antagonistic Ability against Lichi Colletrichum gloeosporiodes Penz of Crude Extract of Bacillus subtilis ON-6

为了探索枯草芽孢杆菌(Bacillus subtilis)对广西重要的药食两用水果——荔枝采后病害的防治效果及其机制,在进行采集、分离、筛选和鉴定的基础上,对枯草芽孢杆菌ON-6菌株发酵液提取拮抗物质方法、拮抗物质的理化性质等方面进行了研究。对ON-6菌株发酵液采用浓盐酸沉淀法及硫酸铵沉淀法,得到的提取液均有抑菌活性,表明ON-6菌株能产生能蛋白类和脂肽类抗生物质。对该菌株的蛋白粗提液进行30～60℃处理30min,其活性保持不变,121℃处理20min,活性丧失不足原有的40%;作用活性pH在5.0～8.0范围内;对胰蛋白酶不敏感,对蛋白酶K和胃蛋白酶部分敏感;对紫外线不敏感。

Bacillus subtilis is a kind of beneficial microbes in biological control and fruit preservation currently.In order to explore the biocontrol effect and mechanism of Bacillus subtilis to litchi postharvest pathogenic fungi in Guangxi,experiments had been carried out to study the method of antifungal substances extraction from fermentation liquid,the partial physical and chemical properties of antifungal substances in Bacillus subtilis strain based on collection,separation,screening and identification.Antifungal substances of strain ON-6 with hydrochloric acid and ammonium sulfate both had inhibitant activity,showed that strain ON-6 were able to produce the proteins and lipopeptide antibiotics simultaneously.The inhibitant activity of crude antifungal protein produced by strain ON-6 was also stable when it was treated with 30-60℃ for 30 minutes,but was depressed less than 40% of the original with 121℃ for 20 minutes.Antifungal substances were partially sensitive to trypsin,and insensitive to proteinase K,pepsin and UV.The inhibitant activity pH rang of antifungal substances was from 5.0 to 8.0.